Speed and torque control of an AC machine typically requires substantial electronic control hardware comprising a rectifier, filter element and an inverter. These elements, which may be water or air cooled, are customarily located remote from the machine and coupled to the machine by a lengthy cable. In an application such as an electric vehicle, this creates packaging difficulties and, without proper shielding, tends to produce significant levels of electromagnetic interference. The end result is a system of less than optimal design, and it may fall short of specified requirements of mass, volume, efficiency, EMI and cost.
To improve these shortcomings, it has been proposed to mount the electronic control hardware in proximity to the machine. See, for example, U.S. Pat. No. to Jensen et al., 4,908,757 issued Mar. 13, 1990. However, the improvements achieved by such arrangements have been limited due to the diverse cooling systems for the machine and the electronic hardware.